I have personally tried to pretty much let the whole MAC Defender trojan thing pass by, since we're not a security website. However, we have an interesting turn of events this week. An article over at Ars Technica quotes several anonymous Apple Store employees as saying that the infection rate of Macs brought into the Apple store has gone up considerably. More interestingly though, Apple's official policy states that Apple Store employees are not allowed to talk about infections to anyone - they're not even allowed to inform Mac owners if they find the infection without the customer's knowledge. Another interesting tidbit: Apple mandates the use of Norton Antivirus on company Macs, according to one Apple Store genius.

Security relates to how well a thing resists attack not how many attack attempts it receives. A thing that resists five out of ten attacks (50%) is more secure than a thing that resists two out of six attacks (33%) even though six attacks is less "market share" than ten attacks.

In terms of market share (popularity), a thing that becomes more popular still had all those un-found vulnerabilities before gaining popularity.

OSX may be getting more attempts against it now due to popularity but exploitable vulnerabilities discovered still existed before now. It was still just as insecure against attempts before as it is now.

Small market share is actually obscurity not security.

Obscurity; I hide behind a corner and you can't see me until you walk around the corner. I'm obscured only until you know where to look.

Security; I hide behind a corner but you can't walk around it and see me because you'd have to get through the locked gate between us.

The first provides no real resistance to finding me where the second does provides some form of resistance to your attempts at walking around the corner.